FAQ: Aftermarket Lowering Springs

Let's be honest, there's maybe 20 of us who are even on here regularly. Of those, maybe 7 would actually be interested in the springs, and of those 7 maybe 4 would actually buy them.

Yeah, I talked to eibach and told them I have seven, and they told me there's no chance of getting an order that small. I've tried talking to custom spring companies and they're either super expensive or not willing to work with me.

I've found at least a half dozen sites that claim to have the sevile springs too, but hopefully this is different.

I'd guinea pig it.

Tyler, did you ask of they could just make more of the Seville or Deville springs? They might be more willing to make something that they already have the specs for.

That is how I originally asked the question. I just asked if they'd do a re-run of the Seville spring, and then he mentioned that if I got enough people, they would run it, but also tweak it to our liking.

As far as the Deville springs, the part numbers for the rear spring insulators are the same on a riv as they are for a bonne, so that's a little bit of verification. (I remembered noticing that when I had to buy them last summer)

For me, it's either the group-buy from Eibach, or $400 for a custom job from Coil Spring Specialists. Being able to dial in your exact rate & height specs is worth the extra. If I can, I'll probably wait a while before doing either (unless the group-buy happens!)

AA, why no coil overs or bags?

$$$$, and I like the way my car rides.

Matt, have you confirmed the existence of these springs? They seem like the same situation as the Seville springs...

Also, a company called Eaton Detroit Springs just got back with me again after I asked about them designing a spring for me/us. They said they have a spring available to drop the front, but they currently don't have one for the back. I'm trying to get them to do a run at a reasonable price.

When I was talking to css, they were extrmemly expensive.

Does anyone here know anything about Eaton springs? I'm going to keep talking to them and see what happens. I'll kelp everyone posted.

http://www.streetbeatcustoms.com/Eibach/Lowering-Springs/Pro_Kit-Lowering-Springs-3872.140/6118/

https://store.outperformance.com/ProductDetails.asp?ProductCode=EIB-3872%2E140&CartID=1

Without digging to deep this is what I found for Seville springs. Obviously call ahead to see if they actually have them.

I've called both of those places along with several others, and they unfortunately don't have them.

Did you call them about the Deville springs too?

It also looks like the FRONT springs on a Grand Prix will work as well, as far as actually fitting. We just need to find a set with a good spring rate and the right height and we should be good. From the looks of it, the WBS springs would be best for ultimate performance while the Eibachs would be the best all-rounders. Stock for stock Raybestos springs are as follows:

Riviera:

 Raybestos:

   Front (5851286):

            Inner Diameter        5.76"
            Wire Diameter        .61"
            Median Design Height 7.50"
            Design Load                1121lb
            Spring Rate                160lb
            Approximate Free Height 14.51"

Grand Prix:

 Raybestos:

   Front (5871139):

            Inner Diameter        5.71"
            Wire Diameter        .56"
            Median Design Height 9"
            Design Load                776lb
            Spring Rate                115lb
            Approximate Free Height 15.75"

Fortunately, somebody on the GP forums has already done the research on GP springs.

http://www.grandprixforums.net/threads/28165-Want-to-lower-your-car-Look-in-here!!

I gave Kevin at Coil Spring Specialties the F41 part numbers and he came back with this:

Front- coil springs - -1.00" trim height & +25% rate increase & +5.0# added weight

Pricing: $225.40 pair

Rear- coil springs - -1.00" trim height & +20% rate increase & +50# added weight

Pricing: $218.10 pair

The added weight in the front is for my bigger brakes and STB, rear is my sub and STB. He initially suggested 20% F/15% R but I showed him how much the car rolled with my autocross videos and suggested a 25% F/20% R and he agreed. Once I get a bunch of Christmas cash and my next paycheck I think I might just give them a go. I plan on taking the junk struts I have now and cutting them open to see if I can fit in a Koni insert or something, then maybe slapping a camber/caster plate on top of it all. Problem is I would have to get a universal one and drill the mounting holes in the plate itself. Rear will just get new OEM (Gabriel?) shocks.

Matt, any chance you think he'd make a second set of those springs with a 2" drop instead?

I got turned off from CSS after the dude a couple pages back had back luck with them, and when I was talking to him, Kevin was really hard to deal with.

Sir Psycho Sexy wrote:

I got turned off from CSS after the dude a couple pages back had back luck with them, and when I was talking to him, Kevin was really hard to deal with.

He's been good with me, and I've read some pretty good reviews online about them so I'm not letting the results of a few turn me away from it. If they send me crappy springs that are completely wrong I'll just send them back and tell them to give my money back.

As for the 2" drop, shoot them an email. If we stuck together at 1" we probably could get a package deal but you would have to upgrade to the 97+ struts, knuckles, and brakes. You can keep the top mount you have because 97 Rivis used the 95/96 top mount but had the 97-99 struts and knuckles.

25% and 20% over the F41's? I don't know man. I don't think I could handle another 25%. 10-15% maybe. I think that another 25% is gonna make it ride like a Go-Kart.

http://95nasta.infiniteboost.com/wp-content/uploads/2010/04/Brake_Strut_Upgrade_1pt1.pdf

http://www.pontiacbonnevilleclub.com/forum/performance-brainstorming/topic22918-20.html

Looks like someone else slapped some W body struts/springs on a Bonneville.......... Hmmmm..... I don't know if I should still build my coilovers or not..... It would be cheaper to get W body parts. I think I'll at least get AGX struts to cut up instead of doing inserts.

Parts still needed:

Struts/inserts
Top mounts (not tearing apart my suspension again, want new/used ones so I can make this a bolt in deal)
Springs
Maybe a bearing setup for where the strut meets the top mount

What ever happened with you and CSS? Just decided you liked this route better?

This route is ultimately cheaper, better performing, and if I don't like the spring I can just try another one for cheap.

I guess that's true. I'm just not sure how I feel about the W body springs. Sure, they might fit, but the W bodies are a lot lighter than Rivs. You have to kind of wonder what that's going to do for ride/performance.

http://www.grandprixforums.net/threads/95314-Eibach-and-ZZP-springs

If someone wants to test if the front GP springs will work for us, there's a good chance to try it right there.....

I picked up a set of stock GP springs today as part of a trade. Slapped them on a pair of old struts (98+ style) and guess what? THEY FIT! Now if somebody good at math wants to help me find the right set of aftermarket springs to buy I'll take the leap and do it. Looking for a 1-2" drop, but don't forget the front end of the GP is lighter than ours so a 1" drop for them might be more for us.

Very nice man! Just an idea, maybe look into front lowering springs designed for a gxp since that has a heavier front end? (At least I'd imagine)

Not sure if they make different sets specifically for the gxp.

Sir Psycho Sexy wrote:

Very nice man! Just an idea, maybe look into front lowering springs designed for a gxp since that has a heavier front end? (At least I'd imagine)

Not sure if they make different sets specifically for the gxp.

Now that is an idea. Not sure about specifics either, but if anything I might be able to find how much a certain spring would drop a GXP vs a regular GP.